I tell people that I temp. This explains why my working hours are all over the place.
Since I do outcalls only, I dress casually and tie my hair up in a messy bun when leaving home and get changed into a nice dress and heels, and take my hair down and spray some perfume in the car when I'm about to go into the booking.
I think if I started to flash the cash, people would start asking questions and it would be a matter of time before I was exposed. So I wear expensive clothes to bookings and regular (sometimes very cheap) clothes to the gym and in my civilian life. It's best not to discuss your finances with anyone, not even a close circle of friends, only you and your accountant/the tax man need to know those details!